The Wärtsilä 31 is available in 8 to 16 cylinder configurations and has a power output ranging from 4.7 to 9.8 MW, at 720 and 750 rpm. The launch of the Wärtsilä 31 introduces a 4-stroke engine having the best fuel economy of any engine in its class. At the same time, it maintains outstanding performance across the complete operating range. Its modular design enables a significant reduction in maintenance time and costs, thereby improving power availability and reducing the need for spare parts. The Wärtsilä 31 is the first of a new generation of medium speed engines, designed to set a new benchmark in efficiency and overall emissions performance. Wärtsilä 31 is recognised by Guinness World Records as the world's most efficient 4-stroke diesel engine